under. and then, there's jason giambi and his gold thong, which he wore to bust out of a slump. yet, superstitious behavior can morph into something more serious, ocd. that affects 200 million adults, as seen in "as good as it gets." >> don't touch. don't touch. >> get a life. >> reporter: but exhibiting ocd behavior doesn't necessarily mean in you have ocd. >> you can count steps. that doesn't mean you have ocd. >> reporter: so, even if you're like de niro's character, don't jump to conclusions. >> if it gets to the point where there are things you can't do because of those superstitions or those behaviors, then you may be on the edge of ocd. >> reporter: this is ocd. this is not. so, line 'em up, sports fans. and may the best team win. if you are exhibiting signs, make sure you see a specialist. signs of ocd, believe it or not, can develop as early as preschool age. it is not diagnosed through a blood test.